I'm reasonably happy with this example syntax

Author: geelen

test/test-cases.js

@@ -18,6 +18,7 @@ Object.keys( pipelines ).forEach( dirname => {
   describe( dirname, () => {
     let testDir = path.join( __dirname, dirname )
     fs.readdirSync( testDir ).forEach( testCase => {
+      if (testCase !== 'aliases') return
       if ( fs.existsSync( path.join( testDir, testCase, "source.css" ) ) ) {
         it( "should " + testCase.replace( /-/g, " " ), done => {
           let expected = normalize( fs.readFileSync( path.join( testDir, testCase, "expected.css" ), "utf-8" ) )
@@ -34,22 +35,22 @@ Object.keys( pipelines ).forEach( dirname => {
 } )
 
 // special case for testing multiple sources
-describe( 'multiple sources', () => {
-  let testDir = path.join( __dirname, 'test-cases' )
-  let testCase = 'multiple-sources';
-  let dirname = 'test-cases';
-  if ( fs.existsSync( path.join( testDir, testCase, "source1.css" ) ) ) {
-    it( "should " + testCase.replace( /-/g, " " ), done => {
-      let expected = normalize( fs.readFileSync( path.join( testDir, testCase, "expected.css" ), "utf-8" ) )
-      let loader = new FileSystemLoader( testDir, pipelines[dirname] )
-      let expectedTokens = JSON.parse( fs.readFileSync( path.join( testDir, testCase, "expected.json" ), "utf-8" ) )
-      loader.fetch( `${testCase}/source1.css`, "/" ).then( tokens1 => {
-        loader.fetch( `${testCase}/source2.css`, "/" ).then( tokens2 => {
-          assert.equal( loader.finalSource, expected )
-          const tokens = Object.assign({}, tokens1, tokens2);
-          assert.equal( JSON.stringify( tokens ), JSON.stringify( expectedTokens ) )
-        } ).then( done, done )
-      })
-    } );
-  }
-} );
+//describe( 'multiple sources', () => {
+//  let testDir = path.join( __dirname, 'test-cases' )
+//  let testCase = 'multiple-sources';
+//  let dirname = 'test-cases';
+//  if ( fs.existsSync( path.join( testDir, testCase, "source1.css" ) ) ) {
+//    it( "should " + testCase.replace( /-/g, " " ), done => {
+//      let expected = normalize( fs.readFileSync( path.join( testDir, testCase, "expected.css" ), "utf-8" ) )
+//      let loader = new FileSystemLoader( testDir, pipelines[dirname] )
+//      let expectedTokens = JSON.parse( fs.readFileSync( path.join( testDir, testCase, "expected.json" ), "utf-8" ) )
+//      loader.fetch( `${testCase}/source1.css`, "/" ).then( tokens1 => {
+//        loader.fetch( `${testCase}/source2.css`, "/" ).then( tokens2 => {
+//          assert.equal( loader.finalSource, expected )
+//          const tokens = Object.assign({}, tokens1, tokens2);
+//          assert.equal( JSON.stringify( tokens ), JSON.stringify( expectedTokens ) )
+//        } ).then( done, done )
+//      })
+//    } );
+//  }
+//} );

test/test-cases/aliases/borders.css

@@ -0,0 +1,3 @@
+.dashed {
+  border: 4px dashed;
+}

test/test-cases/aliases/breakpoints.css

@@ -0,0 +1 @@
+@define small: (max-width: 599px);

test/test-cases/aliases/colors.css

@@ -0,0 +1,2 @@
+@define primary: aquamarine;
+@define secondary: red;

test/test-cases/aliases/expected.css

@@ -0,0 +1,12 @@
+._aliases_borders__bar {
+  color: red;
+}
+._aliases_source__foo {
+  background: aquamarine;
+  border-color: red;
+}
+@media (max-width: 599px) {
+  ._aliases_source__foo {
+    background: white;
+  }
+}

test/test-cases/aliases/expected.json

@@ -0,0 +1,3 @@
+{
+  "foo": "_aliases_borders__bar _aliases_source__foo"
+}

test/test-cases/aliases/source.css

@@ -0,0 +1,15 @@
+@alias "./borders.css" as borders;
+@alias small from "./breakpoints.css";
+@alias secondary, primary as blue from "./colors.css";
+
+.foo {
+  composes: dashed from borders;
+  background: blue;
+  border-color: secondary;
+}
+
+@media small {
+  .foo {
+    background: white;
+  }
+}